Peracid compositions, namely peroxycarboxylic acid compositions, exhibit useful antimicrobial and bleaching activity. Conventional peroxycarboxylic acid compositions typically include short chain peroxycarboxylic acids or mixtures of short chain peroxycarboxylic acids and medium chain peroxycarboxylic acids (see, e.g., U.S. Pat. Nos. 5,200,189, 5,314,687, 5,409,713, 5,437,868, 5,489,434, 6,674,538, 6,010,729, 6,111,963, and 6,514,556, each incorporated by reference in its entirety). However, peracid compositions have a number of limitations, including malodors, stability concerns and insufficient micro efficacy against certain microorganisms.
A majority of existing peracid compositions, including peroxycarboxylic acids, suffer from unacceptable odors which are an inherent disadvantage of the compositions and limit their use in cleaning applications. Often the peracid compositions exhibit a sharp, annoying, or otherwise unacceptable odor that increases as the composition ages, beginning within as soon as a few weeks of formulation. Such malodors significantly limit the applications suitable for using such peroxycarboxylic acid compositions. It would be undesirable to apply such peroxycarboxylic acid compositions to large surfaces areas (e.g. floor cleaners).
There is a need for antimicrobial agents having improved antimicrobial efficacy. Although many peracid compositions have a broad spectrum of antimicrobial properties, many have inadequate activity against hard to kill pathogens, including bacterial spores, fungal spores, and fungi. As a result, killing, inactivating, or otherwise reducing the active population of bacterial spores and fungi on surfaces is particularly difficult. The bacterial spore-forming microorganisms of the Bacillus species are especially important to be aware of during food packaging, particularly during cold or hot aseptic filling of food and beverage, or pharmaceutical, products. Microorganisms of the Bacillus species include Bacillus atropheaus, Bacillus cereus, Bacillus mycoides, Bacillus subtilis, Bacillus anthracis, and Bacillus thuringiensis. These latter microorganisms share many phenotypical properties, have a high level of chromosomal sequence similarity, and are known enterotoxin producers. Bacillus cereus is one of the most problematic because Bacillus cereus has been identified as possessing increased resistance to germicidal chemicals used to decontaminate environmental surfaces. For example, Blakistone et al., Efficacy of Oxonia Active Against Selected Sporeformers, Journal of Food Protection, Volume 62, pages 262 267, report that Bacillus cereus was more tolerant to the effects of conventionally formulated peroxyacetic acid germicides than all other spore-forming bacteria tested, including other Bacillus and Clostridium species.
According to the invention, there is a need for improved stability antimicrobial peroxycarboxylic acid compositions.
It is an objective of the claimed invention to develop improved peracid chemistry for use at lower use concentrations and temperatures.
A further object of the invention is an improved peracid composition with enhanced microbial efficacy for targeting endospore-forming bacilli type bacteria.
A further object of the invention is a method of use for applications employing a lower use concentration of a peracid composition having enhanced microbial efficacy.
A further object of the invention is to provide improved peracid compositions and methods for using the compositions for clean in place (CIP) applications, for example cleaning of tanks, lines, pumps and other process equipment used for processing typically liquid product streams of beverages, in particular for cleaning milking machines.
A still further object of the invention is to provide improved peracid compositions and methods for using the compositions for clean out of place (COP) applications, for example cleaning the interior and exterior surfaces of a wide variety of parts, such as ceramic surfaces, metal surfaces, walls in, wash tanks, soaking vessels, mop buckets, holding tanks, scrub sinks, vehicle parts washers, non-continuous batch washers and systems, and the like.